This research paper presents the design, development, and evaluation of "Sahayak" an innovative Android mobile application engineered to address the multifaceted challenges faced by the growing senior citizen population. In response to prevalent issues of social isolation, emergency vulnerability, and complex management of welfare services, we propose a centralized, user-centric solution built using Kotlin and Android Studio. The application implements a secure authentication framework via SharedPreferences for local session management, leading to a personalized dashboard that dynamically greets users (e.g., "Namaste, Samarth"). Its core architecture features a multi-modular interface providing immediate access to critical services: a prominent SOS and emergency contact system with direct calling to police (100) and ambulance (102), alongside configurable family contacts; dedicated modules for managing pension and life insurance information; and interactive social wellness tools (Talkie and Funzone) designed to combat loneliness and promote cognitive engagement. A key contribution of this work is the deep integration of accessibility and localization, enabling a seamless user experience across multiple Indian languages (Kannada, Telugu, Tamil, Malayalam) to bridge the digital divide. Furthermore, the application includes comprehensive user profile creation and management, capturing demographic and personal data to tailor interactions. By consolidating emergency response, health and finance tracking, and social connectivity into an intuitive, secure, and linguistically adaptable platform, "Sahayak" demonstrates a significant advancement in assistive technology, aiming to enhance the safety, autonomy, and overall quality of life for senior citizens, thereby reducing their dependency on traditional, fragmented support systems.